arXiv subjects

Krishna Pada Das

Publications and source records attributed to Krishna Pada Das.

4 recordsLinked to original sources

arXiv2026

Quark Stars in Ricci-Determinant Gravity with an Interacting Quark Equation of State

In the present study, we explore the fundamental properties of static, spherically symmetric quark stars composed of quark matter with an interacting quark equation of state (EoS) within the framework of Ricci-Determinant gravity. To this end, we adopt the relativistic stellar structure equations for compact objects derived in the literature. Our primary objective is to investigate deviations from General Relativity (GR) in key physical characteristics, particularly the mass--radius relation and stability criteria, arising from the free parameters of this extended gravitational theory. We see that, unlike the hadronic case, the model predicts a reduction in the compactness of quark stars. This parameter is also sensitive to gravitational binding-energy analysis, revealing a breakdown of the assumed universality. Furthermore, the formation of objects with high central densities is restricted by the instability conditions that arise when the contribution of perturbative terms exceeds by approximately half the contribution of ordinary GR, indicating a clear limitation in the theory.

gr-qc↗

arXiv2026

Dark energy stars from the modified Chaplygin gas: $C-I-\Lambda-E_g-f$ universal relations

Dark energy stars (DESs), described by the modified Chaplygin gas (MCG), can be dynamically stable and fall within different observational measurements. In this work, we employ diverse macroscopic properties, such as compactness $C$, moment of inertia $I$, tidal deformability $\Lambda$, gravitational binding energy $E_g$ and $f$-mode nonradial pulsation frequency, to explore whether they are correlated by universal relations (URs). Remarkably, our stellar configurations always obey the causality condition and are compatible with several observational mass-radius constraints. Via the $C-I-\text{Love}-f$ URs, our results reveal that we cannot distinguish quark stars (QSs) from DESs in the sense that DESs satisfy several URs very similar to those of QSs. However, when we involve $E_g$, DESs and QSs can be strongly distinguished through the $I-E_g^{-2}$, $\Lambda-E_g^{-5}$ and $f-E_g^{-2}$ URs. We also make use of these findings and the tidal deformability constraint from the GW170817 event to forecast the canonical properties of a $1.4\, M_\odot$ compact star. Furthermore, we present a set of fine empirical correlations involving the tidal deformability, obtained from an extensive scan of the parameter space of our DE stellar models.

gr-qc↗

arXiv2025

Possible Formation of Traversable Wormholes and Their Thermodynamic Analysis in $\mathcal{F}(Q,\mathcal{L}_{m},\mathcal{T})$ Gravity

In this work, we investigate static and spherically symmetric traversable wormhole solutions within the framework of the extended symmetric teleparallel gravity, specifically the $\mathcal{F}(Q,\mathcal{L}_{m},\mathcal{T})$ gravity theory, where $Q$, $\mathcal{L}_{m}$, and $\mathcal{T}$ are the respective representations of the non-metricity scalar, the matter Lagrangian, and the trace of the energy-momentum tensor. By employing a specific redshift function and deriving the shape function through the Karmarkar condition, we examine the fundamental geometric features required for a viable wormhole structure. The analysis confirms the satisfaction of key conditions such as the throat condition, flaring-out condition, and asymptotic flatness. A detailed study of energy conditions for various values of model parameters reveals that the null energy condition and averaged null energy condition are violated near the throat, indicating the presence of exotic matter. Additionally, thermodynamic quantities such as temperature, pressure, specific heat, work density, and energy flux are analyzed, all of which support the thermal and equilibrium stability of the wormhole. Our findings demonstrate that even in extended theories like $\mathcal{F}(Q,\mathcal{L}_{m},\mathcal{T})$ gravity, exotic matter remains essential for sustaining traversable wormholes. This work lays the foundation for further investigations into their stability under dynamical perturbations and potential astrophysical implications.

gr-qc↗

arXiv2024

Study of Stable Dark Energy Stars in Hořava-Lifshitz gravity

We study the structure and basic physical properties of non-rotating dark energy stars in Ho$\Check{\text{r}}$ava-Lifshitz (HL) gravity. The interior of propsed stellar structure is made of isotropic matter obeys extended Chaplygin gas EoS. The structure equations representing the state of hydrostatic equilibrium i.e., generalize TOV equation in HL gravity is numerically solved by using chosen realistic EoS. Next, we investigate the deviation of physical features of dark energy stars in HL gravity as compared with general relativity (GR). Such investigation is depicted by varying a parameter $ω$, whereas for $ω\rightarrow \infty$ HL coincide with GR. As a results, we find that necessary features of our stellar structure are significantly affected by $ω$ in HL gravity specifically on the estimation of the maximum mass and corresponding predicted radius of the star. In conclusion, we can predict the existence of heavior massive dark energy stars in the context of HL gravity as compared with GR with not collapsing into a black hole. Moreover, we investigate the stability of our proposed stellar system. By integrating the modified perturbations equations in support of suitable boundary conditions at the center and the surface of the stellar object, we evaluate the frequencies and eigenfunctions corresponding to six lowest excited modes. Finally, we find that physically viable and stable dark energy stars can be successfully discussed in HL gravity by this study.

gr-qc↗